Rotary engine.



F. H. LBFTWIGH.

ROTARY ENGINE.

z,PPLIGATION FILED MAY e, 1909.

937,824. v Patented 0015.26, 1909.

2 SHEETS-SHEET 1.

,E attorneys F. H. LEPTWIGH.

ROTRY ENGINE.

APPLIOATION FILED MAY 6,1909.

937,824, Patented Oct. 26, 1909.

2 SHEETS-SHEET 2.

www

at the opposite UNITED STATES PATENT OFETCE.

FREDRIC HARRIS LEFTWICH, OE FLAT WOODS, TENNESSEE, ASSIGNOR 0F ONE-THIRDT0 THOMAS D. TATROM, OF LOVIC, TENNESSEE, AND ONE-THIRD TO GEORGE A.ARY,

0F FLAT WOODS, TENNESSEE.

ROTARY ENGINE.

Specification of Letters Patent.

Patented Oct. 26, 1909.

Application led May 6, 1909. Serial N o. 494,262.

To all 'whom it may concern:

Be it known that I, FREDRIC HARRIS LEFT- wIor-r, a citizen of the UnitedStates, residing at Flat Voods, in the county of Wayne and State ofTennessee, have invented a new and useful Rotary Engine, of which thefollowing is a specification.

This invention relates to rotary engines of that type having an annularsteam cham'- ber in which the head of a rotary piston travels, a slidingabutment being also provided which extends across the steam chamber andis periodically withdrawn therefrom to permit the piston head to pass.

It is the object of the present invention to provide a piston of novelstructure, and also to provide improved means for operating theabutment. f

The invention also has for its object to provide a novel arrangement ofinlet and exhaust ports, together with a valve of great simplicity forcontrolling the inlet port.

A further object of the invention is to simplify the general structureof the engine, and to increase its efficiency.

Vith the foregoing objects in view vthe invention consists in a novelconstruction and arrangement of parts to be hereinafter described andclaimed, reference bein had to the drawing hereto annexed in whic Figure1 is a transverse section of the engine. Fig. 2 is a section on the line2-2 of Fig. 1.

Referring more particularly to the drawings, 5 denotesthe cylinder ofthe engine, the same being provided with a suitable base 6 on which itis supported. Extending lengthwise through the cylinder is a shaft 7provided with a fly-wheel 8 and a pulley 9. The shaft 7 carries a pairof rotary pistons, each of which comprises a substantially semi-circulardisk 10 formed with a hub 11 through which the shaft 7 passes. Thepiston is keyed or otherwise secured to the shaft so as to turntherewith. At one end of the disk 10 is a follower head 12, and end theperiphery of the disk terminates in a cam 13. The bore of the cylinder 5is suitably enlarged to receive the hub 11, and the cylinder is alsoformed with circular recesses 14; in which the piston disks 10 travel,and these recesses are formed with annular steam chambers 15 in whichthe piston heads 12 travel. Between the piston heads 12 and the cam 13,the pistons carry a semi-circular rim or band 16 which is so located asto fit over the ends of the recesses 14 where they merge into the steamchambers 15, whereby that portion of the recesses 14 between the pistonheads and the cams is kept closed, and the entry of steam thereintoprevented.

At 17 is indicated the steam chest of the engine, steam being deliveredthereto by a pipe 18. From this steam chest a port 19 extends to each ofthe chambers 15, and each of said ports is controlled by a valve 2Ocarried by one arm of a lever 21 which i is pivotally mounted at 22 on astud 23 in the valve chest. The other arm of the lever 21 is operativelyconnected to an abutment 24C working in an opening in the cylinder wall,and adapted to be extended radially across the steam chamber 15, andnormally held in thisfposition by means of a' spring 25 mounted in thevalve chest andpressing against that end of the lever to which theabutment is connected. Inasmuch ,as vthe valve 20 is carried by theother arm of the lever, it vwill be seen that when the abutment isextended across the steam chamber 15, the valve 20 will be lifted offthe port 19, and the latter is thus opened and steam is permitted toenter the steam chamber 15. The piston is moved out of the path of thepiston disk 1() and head 12, upon being engaged by the cam 13. When theabutment is thus moved out of the way, the valve 20 closes the port 19and shuts off the steam to the chamber 15. 90 At a point substantiallydiametrically opposit the inlet port 19, is an exhaust port 26 throughwhich steam is exhausted from the chamber 15 when the piston head passesthe same. Behind this exhaust port is located a radially slidingabutment 27 mounted in the walls of the cylinder 5, and held normallyextended across the steam chamber 15 by means of a coiled spring 28.This abutment is pushed outwardly upon being engaged by the cam 13, andthus moved out of the way of the approaching piston disk and head. Whenthe head clears the abutment, the latter drops behind the same andprevents the steam from following the piston head after it passes theexhaust port.

Each of the rotary pistons is provided with the herein described valvemechanism and abutments, and their operation is identical. Therespective piston heads aretlocated 180O apart in order to balance theengme' Y.

The operation of the engine willbe ev1- ldent from the foregoingdescription, but it may be summarized as follows: Fig. 2 shows theabutment 24 extending across the steam chamber l5, and the piston headl2 in position about to uncover the inlet port 19. As soon as the pistonhead passes said port, steam enters the chamber l5 behind the pistonhead, and it is propelled in the direction of the arrow. When the cam 13reaches the abutment 27, the latter is pushed outwardly, and held inthis position by the piston disk l0, the periphery of which fits snuglyon the wall of the steam chamber. As soon as the piston head passes theabutment 27, the latter is pushed forwardly behind the same, and theexhaust through the port 26 takes place. lVhen the cam 13 reaches theabutment 24, said abutment is pushed out of the way of the approachingpiston disk 10, and as soon as the latter passes the'abutment, theabutment drops behind the iston head whereupon the parts are again 1nthe position they occupied at the beginning of the hereindescribedcycle.

It will be seen from the foregoing that the engine is entirely automaticin its action, and all valve gearing is dispensed with, thus Vgreatlysimplifying the structure.

VVhat is claimed is l. In a rotary engine, a cylinder having an annularsteam chamber, and inlet `and exhaust ports to said chamber, a rotarypiston working in the steam chamber, and having a cam, a steam chestfromwhich the inlet port leads, a lever pivotally mounted in the steamchest, a valve controlling the inlet port, said valve being carried byan arm of the lever, and an abutment sliding across the aforesaid and anabutment kslidable across the steamv chamber behind the exhaust port. Y

8. In a rotary engine, a cylinder having an annular steam chamber, andinlet and exhaust ports to said chamber, a rotary piston working in thesteam chambensaid piston having a follower head and a` canna'steamchestfrom which the inlet port leads, a lever pivotally mounted in the steamchest, a valve controlling the inlet port, said valve being carried byone arm of the lever, an

abutment slidable across the steam chamber,

the other arm said abutment being carried by of the lever and operableby the aforesaid cam, and an abutment.extending'jacross the steamchamber behind the exhaust port, the last-mentioned abutment beingoperable Yby the cam to permit passage of the piston, and said abutmentclosing the steam chamber behind the piston, when the latter clears saidabutment. Y

4. In a rotary engine, a cylinder having a circularrecess, and anannular steam chainber communicating with said recess, a rotaryY piston,said piston comprising a semi-circular disk traveling in the aforesaidrecess, and carrying a follower head, and a band extending between theends of the disk, and fitting over the aforesaid recess to close thesame to the steam chamber'.

In testimony thatI claim the foregoing as my own, I have hereto affixedmy signature in the presence of two witnesses; Y FREDRIC HARRISLEFTWICH. Witnesses:

IRA LUNA, Y Ross J. WHITEHEAD.

